1. Field of the Invention
The invention relates to the calibration of writing systems and more specifically to such systems that are modulated to mark a recording medium in a pattern determined by stored information, and to calibration mechanisms for adjusting the writing parameters in real time to modify the characteristics of the marks and their pattern on the medium.
2. Description of the Prior Art
Writing devices are well known for visibly marking a recording medium in response to a signal representing an image or other information. Typical devices convert magnetic or electronic information into a visible pattern on the recording medium. The medium often is rotated relative to a writing head, while the writing head is modulated by the signal, to generate a linear pattern of marks defining raster lines. The head is indexed between rotations to produce parallel raster lines that together define the image. The marks are produced on the media by numerous available technologies including optical energy focused to expose film, inks directed onto the surface of paper, and thermal energy that initiates chemical changes in film and paper.